Network topologies that use a single firewall between a secure internal network and an external network can create a performance bottleneck and a single point of failure. The single firewall may be replaced by a bank of firewalls to increase throughput and provide redundancy. Moreover, network devices such as firewall load balancers can balance the traffic flow across the firewalls in the bank. Firewall load balancers are typically placed on either side of the bank of firewalls between the secure internal network and the external network. A network design with a single firewall load balancer on each side of the bank of firewalls results in two single points of failure at the inside network firewall load balancer and the outside network firewall load balancer.
Conventional firewall load balancing solutions offer an active-passive redundancy design to eliminate single points of failure that may affect the performance of the network. With active-passive redundancy, there are at least two firewall load balancers on each side of the bank of firewalls. For example, a first inside network firewall load balancer handles the traffic flow while a second inside network firewall load balancer is in a standby mode and does not handle traffic unless a failure occurs in the first inside network firewall load balancer. A hot standby routing protocol (HSRP), or other similar protocols, may be used to change the active/standby status of each inside network firewall load balancer. The second inside network firewall load balancer will pick up the traffic flow to and from the inside network. By changing the operating status of the first inside network load balancer from active to standby and the second inside network firewall load balancer from standby to active, typically there is no affect on the active and standby status of first and second outside network firewall load balancers.
Active-passive network designs leave network devices sitting idle. Idle devices are a waste of resources. Additionally, concerns exist that the standby load balancer may not load balance correctly when it becomes active due to misconfigurations, wiring problems, or other possible failures. Therefore, it is desirable to provide failure protection for network traffic without having idle devices in the network design.